Dysequilibrium of the HLA system in certain diseases will be further investigated, particularly Alzheimer's disease which we have found to be significantly HLA correlated. Also we shall test a series of Parkinson's disease patients. The possible influence of HLA on DNA-repair will be further investigated by family studies. We are doing collaborative work evaluating monoclonal antibodies produced in relation to HLA. With these plus screened pregnancy and post-transfusional sera crossabsorbed with lymphoblastoid cell lines, we are testing for new DR specificities. Studies have been initiated to detect HLA-mutants or variants in T-cell culture.